Új és hagyományos irányok a gyermekkori akut lymphoblastos leukaemia biológiájában és ellátásában

Owing to clinical trials and improvement over the past few decades, the majority of children with acute lymphoblastic leukemia (ALL) survive by first-line chemotherapy and combat with the problems of returning to community. However, many patients may have severe acute or late therapeutic side effects, and the survival rate in some groups (e.g., patients with MLL rearrangements, hypodiploidy, IKZF1 mutation or early precursor T cell phenotype) is far behind the average. Innovative strategies in medical attendance provide better clinical outcomes for them: complete gene diagnostics, molecularly targeted anticancer treatment, immuno-oncology and immune cell therapy. The number of genes with identified alterations in leukemic lymphoblasts is over thirty and their pathobiologic role is only partly clear. There are known patient groups where the use of specific drugs is based on gene expression profiling (e.g., tyrosine kinase inhibitors in Philadelphia-like B-cell ALL). The continuous assessment of minimal residual disease became a routine due to the determination of a leukemia-associated immunophenotype by flow cytometry or a sensitive molecular marker by molecular genetics at diagnosis. Epitopes of cluster differentiation antigens on blast surface (primarily CD19, CD20 and CD22 on malignant B cells) can be attacked by monoclonal antibodies. Moreover, antitumor immunity can be strengthened utilizing either cell surface markers (bispecific T cell engagers, chimeric antigen receptor T cell therapy) or tumor-specific immune cells (immune checkpoint inhibitors). This review gives an insight into current knowledge in these innovative therapeutic directions. Orv Hetil. 2018; 159(20): 786-797

Extracelluláris vezikulák és hematológiai malignitásokban játszott szerepük

Absztrakt Extracelluláris vesiculák minden szervezetben képződnek. Három legintenzívebben vizsgált csoportjuk az apoptotikus testek, a microvesiculák és az exosomák. A sejtek közötti kommunikációban, immunreakciókban, angiogenezisben betöltött szerepük csak néhány az eddig megismertek közül. A fiziológiás folyamatok mellett sokféle betegségben leírták változásaikat; a patomechanizmusban betöltött szerepük mellett felvetődik potenciális használatuk biomarkerekként. A szerzők betekintést kívánnak nyújtani az extracelluláris vesiculák kutatásába, kiemelve azt a néhány tanulmányt, amely a hematológiai malignitásokra fókuszált. A microvesiculák és exosomák vérplazmában mért mennyisége, a terápia során megfigyelt minőségi változása miatt felmerült, hogy a diagnosztikában, prognosztikában, illetve a minimális residualis betegség monitorozásában is használhatók lehetnek. Akut myeloid leukaemiában a természetes ölősejtek aktivitásának szupresszálásában bizonyított a blasteredetű exosomák szerepe. Krónikus lymphoid leukaemiában a microvesiculák közreműködése valószínű a gyógyszer-rezisztencia kialakulásában is. Orv. Hetil., 2016, 157(35), 1379–1384. | Abstract Extracellular vesicles are produced in all organisms. The most intensively investigated categories of extracellular vesicles include apoptotic bodies, microvesicles and exosomes. Among a very wide range of areas, their role has been confirmed in intercellular communication, immune response and angiogenesis (in both physiological and pathological conditions). Their alterations suggest the potential use of them as biomarkers. In this paper the authors give an insight into the research of extracellular vesicles in general, and then focus on published findings in hematological malignancies. Quantitative and qualitative changes of microvesicles and exosomes may have value in diagnostics, prognostics and minimal residual disease monitoring of hematological malignancies. The function of extracellular vesicles in downregulation of natural killer cells’ activity has been demonstrated in acute myeloid leukemia. In chronic lymphocytic leukemia, microvesicles seem to play a role in drug resistance. Orv. Hetil., 2016, 157(35), 1379–1384

Circulating microRNAs as minimal residual disease biomarkers in childhood acute lymphoblastic leukemia

Treatment stratification based on bone marrow minimal residual disease (MRD) at set time points has resulted in considerably improved survival in pediatric acute lymphoblastic leukemia (ALL). Treatment response is assessed using bone marrow samples. MicroRNAs (miRs) easily traffic among fluid spaces and are more stable than most other RNA classes. We examined the role of circulating miRs as putative less invasive MRD biomarkers.In an exploratory experiment, expression of 46 preselected miRs was studied in platelet-free blood plasma samples of 15 de novo, 5 relapsed ALL patients and 10 controls by Custom TaqMan Array Advanced MicroRNA Card. Based on their high expression in ALL compared to controls, and on the reduction observed along the induction therapy, four miRs were selected for further analyses: miR-128-3p, -181a-5p, -181b-5p and 222-3p. Their expression was measured by qPCR at 4 time points in 27 de novo ALL patients treated in the ALL IC-BFM 2009 study.The expression of all 4 miRs significantly decreased over the first week of therapy (miR-128-3p: log2 fold change - 2.86; adjusted p 3.6 × 10-7; miR-181b-5p: log2 fold change - 1.75; adjusted p 1.48 × 10-2; miR-181a-5p: log2 fold change -1.33; adjusted p 3.12 × 10-2; miR-222-3p: log2 fold change - 1.25; adjusted p 1.66 × 10-2). However, no significant further reduction in miR expression was found after the 8th day of therapy. Measured drop in expression of 2 miRs at day 8 strongly correlated with day 15 bone marrow flow cytometry MRD results (miR-128-3p: Pearson's r = 0.88, adjusted p = 2.71 × 10-4; miR-222-3p: r = 0.81, adjusted p = 2.99 × 10-3).In conclusion, these circulating miRs might act as biomarkers of residual leukemia. MiR-128-3p and miR-222-3p in blood predict day 15 flow cytometry MRD results 7 days earlier. Although, their sensitivity falls behind that of bone marrow flow cytometry MRD at day 15

Pharmacogenetics of the Central Nervous System—Toxicity and Relapse Affecting the CNS in Pediatric Acute Lymphoblastic Leukemia

Despite improving cure rates in childhood acute lymphoblastic leukemia (ALL), therapeutic side effects and relapse are ongoing challenges. These can also affect the central nervous system (CNS). Our aim was to identify germline gene polymorphisms that influence the risk of CNS events. Sixty single nucleotide polymorphisms (SNPs) in 20 genes were genotyped in a Hungarian non-matched ALL cohort of 36 cases with chemotherapy related acute toxic encephalopathy (ATE) and 544 controls. Five significant SNPs were further analyzed in an extended Austrian-Czech-NOPHO cohort (n = 107 cases, n = 211 controls) but none of the associations could be validated. Overall populations including all nations’ matched cohorts for ATE (n = 426) with seizure subgroup (n = 133) and posterior reversible encephalopathy syndrome (PRES, n = 251) were analyzed, as well. We found that patients with ABCB1 rs1045642, rs1128503 or rs2032582 TT genotypes were more prone to have seizures but those with rs1045642 TT developed PRES less frequently. The same SNPs were also examined in relation to ALL relapse on a case-control matched cohort of 320 patients from all groups. Those with rs1128503 CC or rs2032582 GG genotypes showed higher incidence of CNS relapse. Our results suggest that blood-brain-barrier drug transporter gene-polymorphisms might have an inverse association with seizures and CNS relapse

Subgroups of Paediatric Acute Lymphoblastic Leukaemia Might Differ Significantly in Genetic Predisposition to Asparaginase Hypersensitivity.

L-asparaginase (ASP) is a key element in the treatment of paediatric acute lymphoblastic leukaemia (ALL). However, hypersensitivity reactions (HSRs) to ASP are major challenges in paediatric patients. Our aim was to investigate genetic variants that may influence the risk to Escherichia coli-derived ASP hypersensitivity. Sample and clinical data collection was carried out from 576 paediatric ALL patients who were treated according to protocols from the Berlin-Frankfurt-Munster Study Group. A total of 20 single nucleotide polymorphisms (SNPs) in GRIA1 and GALNT10 genes were genotyped. Patients with GRIA1 rs4958351 AA/AG genotype showed significantly reduced risk to ASP hypersensitivity compared to patients with GG genotype in the T-cell ALL subgroup (OR = 0.05 (0.01-0.26); p = 4.70E-04), while no such association was found in pre-B-cell ALL. In the medium risk group two SNPs of GRIA1 (rs2055083 and rs707176) were associated significantly with the occurrence of ASP hypersensitivity (OR = 0.21 (0.09-0.53); p = 8.48E-04 and OR = 3.02 (1.36-6.73); p = 6.76E-03, respectively). Evaluating the genders separately, however, the association of rs707176 with ASP HSRs was confined only to females. Our results suggest that genetic variants of GRIA1 might influence the risk to ASP hypersensitivity, but subgroups of patients can differ significantly in this respect

Pharmacogenetics of anthracyclines.

Anthracyclines constitute a fundamental part of the chemotherapy regimens utilized to treat a number of different malignancies both in pediatric and adult patients. These drugs are one of the most efficacious anticancer agents ever invented. On the other hand, anthracyclines are cardiotoxic. Childhood cancer survivors treated with anthracyclines often undergo cardiac complications which are influenced by genetic variations of the patients. The scientific literature comprises numerous investigations in the subject of the pharmacogenetics of anthracyclines. In this review, we provide a comprehensive overview of this research topic. Genetic variants are proposed targets in the personalized treatment in order to individualize dosing and therefore reduce side effects

Associations of rs2055083 with the occurrence of <i>E</i>. <i>coli</i>-ASP hypersensitivity in the total cohort and in different risk groups.

<p>Results that reached the significance threshold (FDR(α) = 5%; p≤ 6.76E-03) are in bold.</p><p>Associations of rs2055083 with the occurrence of <i>E</i>. <i>coli</i>-ASP hypersensitivity in the total cohort and in different risk groups.</p

Associations of rs707176 with the occurrence of E. coli-ASP hypersensitivity in subgroups created by risk category and gender.

<p>Results that reached the significance threshold (FDR(α) = 5%; p≤ 6.76E-03) are in bold.</p><p>^a the cofactor of ASP dosage during induction was not included in the analysis due to numerical problems of the logistic regression model created by the presence of cell values equal to zero.</p><p>^b not analysed due to the presence of cell values equal to zero.</p><p>Associations of rs707176 with the occurrence of E. coli-ASP hypersensitivity in subgroups created by risk category and gender.</p